Hidden voids in castings

[303Guy]

Out of a small batch of castings, two were a bit under weight. They looked great but anyway. I tried closing the hollow nose a bit and the voids within them collapsed, revealing them.

http://i388.photobucket.com/albums/oo327/303Guy/MVC-861F.jpg

They looked like this before the treatment.
http://i388.photobucket.com/albums/oo327/303Guy/MVC-860F-1.jpg

Without weighing those would have been 'inexplicable' flyers. We're talking 1gr underweight on a 204.5gr nominal boolit!

[Bret4207]

That's the one problem I don't know how to fix. Well, I do actually, but swage dies and stuff get real expensive, real fast.

The funny thing is you can weigh every boolit and shoot 10 that are within .1 of a grain and shoot 10 that are all over the scale and if the gods of shooting smile on you (or decide to screw with you) the "bad" ones might shoot just as well or better than the "good" ones! IT won;t happen every time, but it will happen enough to make you wonder just what you don't know!

[sundog]

That's the whole point about weighing [match] boolits - eliminate flyers. It takes only a few minutes, and the results are worth it.

[MT Chambers]

Weight differences of 1 gr. don't seem to matter as much in my accuracy tests, other factors seem to show more on the targets ie: neck tension issues, shooter error, etc. In fact, sometime I shoot rejects and the results downrange are the same as my match selections.

[Calamity Jake]

I weight sort all my military BR match boolits to .3 grains and still get at least one unexplained flier in a 10 round string.
That one flier may be 1/2" out of the group or 1 1/2" All else being equal the only explanition has to be VOIDS!!!!!! Even small enough to not be detected by the scales. They drive me bonkers.

[sundog]

Fit is King.

Case prep is Queen.

Like Jake says, "All else being equal..."

I'll continue to weight sort match boolits.

[qajaq59]

I think where the voids are in relation to the center probably has a lot to do with how far off they fly.

[Alex Hamilton]

I weight sort all my military BR match boolits to .3 grains and still get at least one unexplained flier in a 10 round string.
That one flier may be 1/2" out of the group or 1 1/2" All else being equal the only explanition has to be VOIDS!!!!!! Even small enough to not be detected by the scales. They drive me bonkers.

Jake,

What you are experiencing could also be "lube purging" and is not at all uncommon in smallbore (.22 rimfire) target shooting, especially when cheaper ammunition is used. What happens is that every 9th or 10th shot the bullet clears out accummulated lubricant and is deflected slightly out of the group.

If your bullet has 2 cannelures, try lubricating only the bottom one.

Do tell us how you get on.

Alex

[jimmeyjack]

I think where the voids are in relation to the center probably has a lot to do with how far off they fly.

I agree.

[303Guy]

Considering that the one boolit was only .5gr below my cut-off and the heaviest boolit was .5gr above nominal, that same heavy could have carried a .5gr cavity and been on spec!

I made an observation after refilling the pot with a new mix - I wanted to compare the alloy so I heated up the mold in the pot and cast two samples. They weighed exactly the same! I also found the boolits cast into weight catagories which is curious. It seems that the weight is a function of mold to alloy temperature. With my mold, if the alloy is cooler and the mold is cooler, I get radial 'shut' crinkles.

These are from two different molds. (My molds are weight adjustable).
http://i388.photobucket.com/albums/oo327/303Guy/CastingDefects.jpg The 'cold shuts' and the voids coincide - curious.

[357maximum]

I got a little story I'd like to tell.:bigsmyl2:

A few years back I made a deal with an older...ahem senior[smilie=s: member here. This deal included him sending me some very large batches of .30 caliber boolits. When I finally :bigsmyl2: recieved the boolits I was a bit shocked/awed/ and a few other words with the way the boolits' bases looked. I knew it was just wrong for the bases to have slight tears and always went way out of my way to ensure my bases looked perfect..why would he send me this many junky boolits????

I eventually worked up the cahoneys to say something to this grumpy old codger and asked politely as I could.....why he sent me boolits with all the bases torn out, I thought you would know better than that. He simply asked me if I had shot any of them. I said no, whats the point? He said go shoot them and report back.

Well I did go shoot them and they grouped better than any boolits I had ever made in the calibers I shot them in. I reported back and he went into the "WHY FORS" and I thought he was totally nutsy cuckoo.

The next time I cast rifle boolits I cast them warmer/faster than normal so that all the bases were consistantly slightly torn just like his were. My boolits also shot better than they ever had...HMMMMMM SAYS I.

Guess what...when you cast a bit warmer and forget about the pretty sprue shear you effect the rest of the boolit in positive ways. There is never a wrinkle, no detectable errant shot "FLIERS" and the mean average weight variation comes way way down.............and you shoot smaller groups. I learned alot about casting in that weird drawn out lesson.

I still do not make my sprue tears as LARGE as he does, but I learned alot about consistent casting from him. Tempo is easier to maintain when casting faster/warmer which leads to more consistent boolits and you do not get the dreaded voids, boolit weights are faaaaaaaaaarrrrrrrrrrrrrrr more consistent, even though the back end looks like a small moon crater ............hmmmmmmmmmmmmm again.

Thank you ya old ornry coot.[smilie=s:

[Bret4207]

The next time I cast rifle boolits I cast them warmer/faster than normal so that all the bases were consistantly slightly torn just like his were. My boolits also shot better than they ever had...HMMMMMM SAYS I.

Guess what...when you cast a bit warmer and forget about the pretty sprue shear you effect the rest of the boolit in positive ways. There is never a wrinkle, no detectable errant shot "FLIERS" and the mean average weight variation comes way way down.............and you shoot smaller groups. I learned alot about casting in that weird drawn out lesson.

[smilie=s:

Noobs need to read the above about 50 times and commit it to memory.

[Doby45]

http://i388.photobucket.com/albums/oo327/303Guy/CastingDefects.jpg

Those are little lead "turds", do you shoot them like that?

[sagacious]

...
The 'cold shuts' and the voids coincide - curious.
303Guy,
Reading through this thread, I was going to reply that the cold-shuts and voids would coincide, and this is the basis for understanind/fixing your problem, but you already noted that. Very good!

I have experienced the same problem occasionally with my push-through molds. Voids are a problem with that mold type. The problems that cause/affect this are primarily:
Lack of mold venting at the void area.
Low-fluidity alloy.

OK, bear with me on this. As the metal fills the mold, it 'sloshes' in with a regular pattern. The very first portion of metal entering the mold cools off rapidly and approaches slushiness or what's called the 'coherency point.' That's the point where the flow of the metal is impeded or stopped. You can imagine the first 'splash' of metal causing a wave of heat to propagate through the mold-- the following molten metal benefits from that heat and fills out fine. But the first portion does not, and it cools quickly and can form the cold-shuts and/or trap a bubble of air. The two almost always coincide, as it's the same problem that forms them. Sometimes drossing of certain alloys can cause the exact same symptoms, even though heat loss is not the cause.

Since venting in that area is not possible with this mold type, the fluidity aspect is the one to address. Increasing the heat or increasing the tin content will reduce the fluidity.

Adjusting the alloy fluidity through adding tin is preferable, as it (1) reduces the melting point, which minimizes the effect of the 'heat wave' effect; (2) reduces oxide layer formation, which is an important factor even inside the cavity; (3) increases the temp range between the melting point and pouring temperature without actually increasing temp and thus increasing drossing; (4) increases solubility of Sb in the alloy. These things will help with reducing the void rate.

Increasing the mold temp will help also, and avoids problems associated with increasing the temp of the melt. Your pics show that too-low mold temp may be a primary factor to consider.

To test alloy fluidity, pour a bunch of castings with your existing alloy. Then add 0.5%Sn and pour a bunch more castings. Add another 0.5% and pour the same amount again. Compare the weight disparity of the three groups. If the addition of tin decreased the void rate, then you can add another 0.5% and test again. More than 2% total tin content is not likely needed, and do not add more tin if the previous additions did not help. For most consistent results, you will have to keep strict account of the alloy used for that mold.

If for some reason, that does not reduce the void rate, you can try casting at slightly higher temp, or open the sprue hole by 0.5mm. Both those can change the fill dynamics. Good luck.

[StarMetal]

I got a little story I'd like to tell.:bigsmyl2:

A few years back I made a deal with an older...ahem senior[smilie=s: member here. This deal included him sending me some very large batches of .30 caliber boolits. When I finally :bigsmyl2: recieved the boolits I was a bit shocked/awed/ and a few other words with the way the boolits' bases looked. I knew it was just wrong for the bases to have slight tears and always went way out of my way to ensure my bases looked perfect..why would he send me this many junky boolits????

I eventually worked up the cahoneys to say something to this grumpy old codger and asked politely as I could.....why he sent me boolits with all the bases torn out, I thought you would know better than that. He simply asked me if I had shot any of them. I said no, whats the point? He said go shoot them and report back.

Well I did go shoot them and they grouped better than any boolits I had ever made in the calibers I shot them in. I reported back and he went into the "WHY FORS" and I thought he was totally nutsy cuckoo.

The next time I cast rifle boolits I cast them warmer/faster than normal so that all the bases were consistantly slightly torn just like his were. My boolits also shot better than they ever had...HMMMMMM SAYS I.

Guess what...when you cast a bit warmer and forget about the pretty sprue shear you effect the rest of the boolit in positive ways. There is never a wrinkle, no detectable errant shot "FLIERS" and the mean average weight variation comes way way down.............and you shoot smaller groups. I learned alot about casting in that weird drawn out lesson.

I still do not make my sprue tears as LARGE as he does, but I learned alot about consistent casting from him. Tempo is easier to maintain when casting faster/warmer which leads to more consistent boolits and you do not get the dreaded voids, boolit weights are faaaaaaaaaarrrrrrrrrrrrrrr more consistent, even though the back end looks like a small moon crater ............hmmmmmmmmmmmmm again.

Thank you ya old ornry coot.[smilie=s:

Yup, been doing it most of my casting life. He and I kinda of laugh at you and some other friend that mocked us on certain things, such at a little tearing out of the sprue, and now you two preach it. :bigsmyl2::kidding:

[Old Caster]

I think it is a good Idea to ladle cast whenever the bullet starts to get long compared to the diameter because as previously stated the lead that gets in there first has a chance to cool too quickly and cause problems. My ladle will pour about 800 grains so it will jam in there quickly but it is necessary to hold it on the sprue hole for 4 or 5 seconds after the pour so it can solidify at the top too. This way you get good fill and a good sprue cut. The only ordinary reasons for a bad fillout is oil or dirt in the mould, not hot enough (lead or mould), and not enough tin or an alloy that has something strange in it. Generally I bottom pour because it is so much faster but if dificulties prevail, try ladle casting.

[kbstenberg]

I don't want to hijack the thread. But could someone tell me more about this torn basses business. Or send me to a thread for more information!
Kevin

[303Guy]

Ya mean I bin fuss'n all dis time fer nuttin'!?[smilie=b::killingpc[smilie=b:

No one can fault my boolit bases. They come out perfect then when I fire 'em they come out like this!

http://i388.photobucket.com/albums/oo327/303Guy/MVC-875F.jpg

That's why I try keep the 'eye' of the patch tail as uniform and central as possible.

Well, now that I know what wrong, I can start on making it right. I've actually figured a way to increase the sprue flow speed. I shape it like a nozzle with smoothly blending curves. All that helps little if the air vents don 't work. That's poses a new problem - if the air vents work too well I get a terrible nose on the boolit.:(

Mmmm.... I think I've learned a heap from this one. Thanks all.:drinks:

P.S. No, I don't shoot those crappy castings.:mrgreen: That mold was a bit of a failure - part of the learning curve.[smilie=1: I do use them for load development in the 'test tube' where no accuracy is required. I figure if those things won't flame cut niether will a good casting. I hope!:roll:

[303Guy]

I don't want to hijack the thread. But could someone tell me more about this torn basses business.By all means go for it! I want to know more too!:drinks:

[leftiye]

Hotter is better - minor frosting. If your sprues tear wait a second or two longer and they'll come out perfect. Oops, I forgot that most of us don't control mold temp with a mold heater, but only by melt temp and casting speed. Sooo, faster is better ( until you get sloppy, and only until your mold is too hot).

[357maximum]

Yup, been doing it most of my casting life. He and I kinda of laugh at you and some other friend that mocked us on certain things, such at a little tearing out of the sprue, and now you two preach it. :bigsmyl2::kidding:

Preaching:groner:.................I think I would find the collar a bit too tight.


I don't want to hijack the thread. But could someone tell me more about this torn basses business. Or send me to a thread for more information!
Kevin

I think we will let Joe splain it, he seems to have a better grasp on it than I do. I am just a mere mortal that likes to share his successes with others.

[StarMetal]

Preaching:groner:.................I think I would find the collar a bit too tight.



I think we will let Joe splain it, he seems to have a better grasp on it than I do. I am just a mere mortal that likes to share his successes with others.


I do believe we should let that "old man" who gave you the bullets explain it.[smilie=f:

[robertbank]

The way I figure it I have enough negatives when I shoot cast rifle bullets going for me that I decided long ago to use a simple approach. I turn my RCBS ProMelter to it's highest setting, when the light goes out I begin casting with warmed up molds from sitting on the edge of the pot. As soonas I get full fill-out boolits dropping from the mold I start casting inearnest with at least three different 4 cavity molds dropping all my castings into cold water for later sorting.

I am afraid it is not all that scientific but it seems to work for me. To date I have managed, with a scope on my Longbranch, two 5 shot groups of approx. 1 25 inches at 100 yards, I have also shot minute of berm with the same rifle with different loads.

I do believe that casting hot is the answer for me. I get much better mold fill out. By casting with more than one mold I can keep the molds from getting to hot. Ummm never spent much time looking at the bases. Maybe I should. I did spend some time sorting my boolits by weight +or- 1 grain. Did it for awhile but I still seemed to get about the same results. This is not surprising given the absence of any real skill at rifle shooting by me.:)

Take Care

Bob

[303Guy]

This has been an informative thread. Funny too!:bigsmyl2:

I'd forgotten about frosting - I don't get near it with whatever setup I'm using. I've sure had all the colors of the rainbow with the last lot (prompted me to have a look at the sticky on colors - good thread!) I've cast with the melt glowing red (no rainbow colors) and the mold so hot it gets boring waiting for the metal to solidify and still no frosting. Justs my molds and alloy, no doubt.

[45 2.1]

I still do not make my sprue tears as LARGE as he does, but I learned alot about consistent casting from him. Tempo is easier to maintain when casting faster/warmer which leads to more consistent boolits and you do not get the dreaded voids, boolit weights are faaaaaaaaaarrrrrrrrrrrrrrr more consistent, even though the back end looks like a small moon crater ............hmmmmmmmmmmmmm again.

Thank you ya old ornry coot.[smilie=s:

Took you long enough to learn something about it, BUT all the reasons you listed are just side effects as to the why I do it like that. That big reason is boolit hardness...... or lack of it in the right places when water dropping.

Most of the things I do are crossways to the way you fellows think things work. Hot is not better.... it is a crutch (your cycleing your mold temperature over too wide a range for consistency). Learn how to make consistent weight boolits (which usually means dipper casting, most bottom pour pots do not put out enough pour volume over a certain size/weight boolit)............. that in itself will get you a long ways down the road. If you can't cast a 30 caliber boolit with the extreme spread of +/- 0.1 gr. you need to work on it a lot. With good casting technique a 0.1 gr. total weight spread is quite doable without being tedious about it. Get tedious and you can cast 45 caliber rifle boolits with no weight spread. No matter... you guys do what you want and believe whatever you want. There are people here who do things most think unbelieveable. Neither side is going to change much.

[Bret4207]

303Guy,
Reading through this thread, I was going to reply that the cold-shuts and voids would coincide, and this is the basis for understanind/fixing your problem, but you already noted that. Very good!

I have experienced the same problem occasionally with my push-through molds. Voids are a problem with that mold type. The problems that cause/affect this are primarily:
Lack of mold venting at the void area.
Low-fluidity alloy.

OK, bear with me on this. As the metal fills the mold, it 'sloshes' in with a regular pattern. The very first portion of metal entering the mold cools off rapidly and approaches slushiness or what's called the 'coherency point.' That's the point where the flow of the metal is impeded or stopped. You can imagine the first 'splash' of metal causing a wave of heat to propagate through the mold-- the following molten metal benefits from that heat and fills out fine. But the first portion does not, and it cools quickly and can form the cold-shuts and/or trap a bubble of air. The two almost always coincide, as it's the same problem that forms them. Sometimes drossing of certain alloys can cause the exact same symptoms, even though heat loss is not the cause.

Since venting in that area is not possible with this mold type, the fluidity aspect is the one to address. Increasing the heat or increasing the tin content will reduce the fluidity.

Adjusting the alloy fluidity through adding tin is preferable, as it (1) reduces the melting point, which minimizes the effect of the 'heat wave' effect; (2) reduces oxide layer formation, which is an important factor even inside the cavity; (3) increases the temp range between the melting point and pouring temperature without actually increasing temp and thus increasing drossing; (4) increases solubility of Sb in the alloy. These things will help with reducing the void rate.

Increasing the mold temp will help also, and avoids problems associated with increasing the temp of the melt. Your pics show that too-low mold temp may be a primary factor to consider.

To test alloy fluidity, pour a bunch of castings with your existing alloy. Then add 0.5%Sn and pour a bunch more castings. Add another 0.5% and pour the same amount again. Compare the weight disparity of the three groups. If the addition of tin decreased the void rate, then you can add another 0.5% and test again. More than 2% total tin content is not likely needed, and do not add more tin if the previous additions did not help. For most consistent results, you will have to keep strict account of the alloy used for that mold.

If for some reason, that does not reduce the void rate, you can try casting at slightly higher temp, or open the sprue hole by 0.5mm. Both those can change the fill dynamics. Good luck.

Isn't that heat wave going to be relative as mould temp goes up?

[BABore]

I got a little story I'd like to tell.:bigsmyl2:

A few years back I made a deal with an older...ahem senior[smilie=s: member here. This deal included him sending me some very large batches of .30 caliber boolits. When I finally :bigsmyl2: recieved the boolits I was a bit shocked/awed/ and a few other words with the way the boolits' bases looked. I knew it was just wrong for the bases to have slight tears and always went way out of my way to ensure my bases looked perfect..why would he send me this many junky boolits????

I eventually worked up the cahoneys to say something to this grumpy old codger and asked politely as I could.....why he sent me boolits with all the bases torn out, I thought you would know better than that. He simply asked me if I had shot any of them. I said no, whats the point? He said go shoot them and report back.

Well I did go shoot them and they grouped better than any boolits I had ever made in the calibers I shot them in. I reported back and he went into the "WHY FORS" and I thought he was totally nutsy cuckoo.

The next time I cast rifle boolits I cast them warmer/faster than normal so that all the bases were consistantly slightly torn just like his were. My boolits also shot better than they ever had...HMMMMMM SAYS I.

Guess what...when you cast a bit warmer and forget about the pretty sprue shear you effect the rest of the boolit in positive ways. There is never a wrinkle, no detectable errant shot "FLIERS" and the mean average weight variation comes way way down.............and you shoot smaller groups. I learned alot about casting in that weird drawn out lesson.

I still do not make my sprue tears as LARGE as he does, but I learned alot about consistent casting from him. Tempo is easier to maintain when casting faster/warmer which leads to more consistent boolits and you do not get the dreaded voids, boolit weights are faaaaaaaaaarrrrrrrrrrrrrrr more consistent, even though the back end looks like a small moon crater ............hmmmmmmmmmmmmm again.

Thank you ya old ornry coot.[smilie=s:

Since I learned some from the same ole codger, I will expand a bit on what Mike covered.

It's not how hot you run your alloy and how much tin you feel the need to dump in the pot. Nor is it the need to run things so hot that boolits look like galvanized sheet metal. It's all about managing your mold block temperature correctly. The old coot mentor does this to get a consistent and high enough mold temperature so that the 50/50 WW-Pb alloy boolits will drop from the mold and into water at a very precise and narrow temperature range. This gives a predictable hardness when aged properly and is very close to simulating a lower temperature oven heat treatment. How often do you hear members saying that when they WD WW alloy they get 20-22 bhn, but when they oven HT the same alloy it gets 28-30 bhn? Does that tell you anything? It tells me that you weren't maintaining your mold at the correct and high enough temp so that they hit the water at the same temperature as when removed from the oven at 425-475 F. When you wait for the sprue to solidify so you get that "textbook" clean cut, you are letting the mold suck heat out of the boolit very rapidly. At this point the boolit temperature is just at the threshold where it will HT. Sometimes just above, sometimes just below. By tearing a bit of sprue, your up above that threshold. My Wd boolit attain the same hardness as ones I oven HT.

Another reason the ole timer does what he does it that he's interested in expanding hunting boolit. Most all of our small group hunt, so we use an alloy of 50/50 WW-Pb plus a little bit (1/2% or less) of tin. This alloy is tough and will expand even when HT'd. If it is oven HT'd at 435 F and quenched, it will not harden to the core on boolits bigger than 30 cal. or so. Running the mold block temp. so that your just tearing out sprue is about the same temperature as the oven. I've explained this before and have done expansion tests as well as posted pictures. An antimonial alloy can be heat treated at a specific temperature. It has a minimum temp, with the max being just below the slump point. If it's hot enough, around 425 with this alloy, it will harden. If it's below that temp. it won't. This casting technique allows the boolit temp to be just above the critical HT point. When the outside or shell is rapidly quenched, heat is drawn out of the boolits core by convection. Being that the entire boolit is just above the critical HT temp., the core drops below that point before it can be rapidly quenched. Result, hard shell and soft core. The bigger the caliber, the greater the affect.

So how does that relate to the subject of internal voids or air pockets? It goes back to the consistency of block temperature. Your mold is running hot enough that it takes care of the common poor fillout and wrinkle problems. That's the boolit's outside. On the inside you will still get some air pockets and voids. By running a very controlled block temperature they will be minimized and more consistent. This is all tied in with how the cavity is filled. Flow rate into the mold is important. It is directly tied in with cavity venting. A well vented mold can literally be shoved full of lead. A poorly vented one may work better with a steady stream directly through, or to one side of the sprue hole. The air has to get out if you want to reduce voids. Because of head pressure, BP pots can cause alot of turbulance which can work both for and against you at times. If you need a higher flow rate or volume for big boolits, it can get even worse. A ladle doesn't have near the head pressure even with a large pour hole. But a ladle only holds 2-6 cavities worth of alloy. When you get toward the end of the ladle-full, pressure goes down. Change the pressure, change the boolit. I either refill the ladle when half empty or use a large enough ladle like the Rowell #1.

So, how were we taught to do all this correctly? #1 is get a small, high speed fan that can be clamped between the pot and your cut sprue box. Not only is it used for maintaing block temperature, but also for keeping the fumes off you. I run all my alloys, including Pb, Pb/tin mixes, WW's, and 50/50 WW-Pb at 700 to 775F. Mostly at 750 F works for all.

Preheating the mold
Hot plates are fine, but they don't usually get the mold hot enough. I used to preheat, then cast til the mold seemed like it was hot enough. I usually had to apply smoke to aluminum molds to get rid of those final little wrinkles and problem areas. No more! Whether the mold is preheated or not, I dip the front corner of the mold and part of the sprue plate in the pot. Anywhere from 15 to 60 seconds. On the first pour, the sprue will remain liquid for 20-30 seconds or more. I hold it in front of the fan to speed things up. The dropped boolits will look like galvanized steel. Too hot, but well filled out with no smoking of the cavities on the first shot. Cool the open mold in front of the fan for about 5 seconds and refill. Watch how long it takes for the sprue to solidify. Keep repeating until it takes the sprue about 3-4 seconds to soldify and change color. The dropped boolits will be just below the frosty stage and shiny. Your ready to roll now. Throw all your boolits back into the pot.

Casting and Cooling
With the mold at the proper temperature, maintain the 3-4 second sprue freeze/change time. Then cool the sprue in front of the fan for a 3 count and cut it. If you tear a bit of sprue, fine. Your just about perfect. If it's a clean cut sprue, decrease your fan time accordingly. Immediately dump your boolits into water. Now, depending on how the mold runs, you may have to cool the open mold in front of the fan. Sometime no, sometimes as long as 6 seconds. You have to determine this based on that 3-4 second sprue freeze time. Once you establish the proper timing, stay with it and you will be very consistent in boolit weight, size, and internal voids.

Quality Control
When you get the cadence down, and your water dropping your boolits, fish out about every tenth or fifteenth drop or just drop them on a towel for a quick inspection. Everytime I read of someone water dropping 500 boolits and find out that 60% of them are bad, I feel like tearing what little hair I have left, out. It's just plain stupid and easily remedied. LOOK!:shock:

When you believe you have it all down pat, check your work. I have weighed alot of boolits. Yes to sort out the high's and lows, but also to check my technique and adjust it if needed. Out of a 4 cavity, 420 grain, 458 mold, it is very easy to get less than a +/-0.5 grain spread. The last 22 cal's I cast, I sent to Beagle to play with. From a 6C mold, the entire batch had a total variance of 0.15 grains. They were poured with a Rowell ladle. If your weight variance is high, start out by measuring boolits with a good micrometer to see if you have any variance there. It does you absolutely no good to weight sort if your size varies. A larger diameter boolit with lots of voids could weigh the same as a smaller one with almost no voids.

So, that my 2 cents on what I learned. Take it for what it's worth.

[StarMetal]

Ha ha ha ha ha.....the both of you still missed something else he's not telling you. He told you about the consistency, but not the other reason. Let's see if you can figure it out.[smilie=w:

[Dannix]

Noobs need to read the above about 50 times and commit it to memory.
It's one of the few posts I've actually reread a couple of times to make sure it sunk in.

This forum has lifetimes of experience. :)

[BABore]

Ha ha ha ha ha.....the both of you still missed something else he's not telling you. He told you about the consistency, but not the other reason. Let's see if you can figure it out.[smilie=w:

Yuck it up Joe! I still have some of your boolits. Want that I post some pictures?:grin::kidding:

[Calamity Jake]

Jake,

What you are experiencing could also be "lube purging" and is not at all uncommon in smallbore (.22 rimfire) target shooting, especially when cheaper ammunition is used. What happens is that every 9th or 10th shot the bullet clears out accummulated lubricant and is deflected slightly out of the group.

If your bullet has 2 cannelures, try lubricating only the bottom one.

Do tell us how you get on.

Alex

Been there!! I've cut the lube(felix) all the way down to just the GC shank and one groove above it. It didn't make a difference.
I'm now trying lars 2500+ but I don't think it will make a differnce.
I still think it is voids!!!!

[45 2.1]

When you wait for the sprue to solidify so you get that "textbook" clean cut, you are letting the mold suck heat out of the boolit very rapidly. At this point the boolit temperature is just at the threshold where it will HT. Sometimes just above, sometimes just below. By tearing a bit of sprue, your up above that threshold. My Wd boolit attain the same hardness as ones I oven HT.

Another reason the ole timer does what he does it that he's interested in expanding hunting boolit. Most all of our small group hunt, so we use an alloy of 50/50 WW-Pb plus a little bit (1/2% or less) of tin. This alloy is tough and will expand even when HT'd. If it is oven HT'd at 435 F and quenched, it will not harden to the core on boolits bigger than 30 cal. or so. This effect can be taken somewhat lower in caliber down to the 25 if lesser WW content is used also and a long cure time, even when water dropping is done. The temperature range for this is a little different and has a very narrow window.Running the mold block temp. so that your just tearing out sprue is about the same temperature as the oven. I've explained this before and have done expansion tests as well as posted pictures. An antimonial alloy can be heat treated at a specific temperature. It has a minimum temp, with the max being just below the slump point. If it's hot enough, around 425 with this alloy, it will harden. If it's below that temp. it won't. This casting technique allows the boolit temp to be just above the critical HT point. When the outside or shell is rapidly quenched, heat is drawn out of the boolits core by convection. Being that the entire boolit is just above the critical HT temp., the core drops below that point before it can be rapidly quenched. Result, hard shell and soft core. The bigger the caliber, the greater the affect.

So, that my 2 cents on what I learned. Take it for what it's worth.

Not too bad a post......................... some refinement and you'll have it.

[BABore]

Not too bad a post......................... some refinement and you'll have it.

My finners got sore typing. A book could be written on this subject though.

[45 2.1]

My finners got sore typing. A book could be written on this subject though.

Yes, I do understand about sore fingers...three in my case. A rather large book and a lot of disbelievers...........................

Until you experience this happening, you won't believe it either.

[BABore]

Yes, I do understand about sore fingers...three in my case. A rather large book and a lot of disbelievers...........................

Until you experience this happening, you won't believe it either.

So true. How many boolits one can cast an hour and "couple inch groups" tend to lull the masses.

Here's a 50/50 WW-Pb boolit that was water dropped for a 22 bhn shell hardness. 480 Ruger, 400 gr at 1,250 fps. Went through 1/2" osb, then into soft loam soil at 50 yards. Shot by you BTW.

[Dannix]

What ovens are you guys using for oven HT? Always been curious about this. I assume you don't just do it in the kitchen. I had wondered why you guys bother to oven HT at all and don't just water drop from the mold. A soft core makes sense.

On the issue of expansion + hardness, you hoary headed veterans ever tried Pb/Sn/Cu? leftiye gave me the idea of trying it.

[45 2.1]

So true. How many boolits one can cast an hour and "couple inch groups" tend to lull the masses.

Here's a 50/50 WW-Pb boolit that was water dropped for a 22 bhn shell hardness. 480 Ruger, 400 gr at 1,250 fps. Went through 1/2" osb, then into soft loam soil at 50 yards. Shot by you BTW.

Yep, I remember that soil up there.............. Yuckkkkk. Sand, loam and very little other redeeming attributes. Makes for really poor boolit expansion media. You HP that sucker and it will do right well.

[45 2.1]

What ovens are you guys using for oven HT? Always been curious about this. I assume you don't just do it in the kitchen. I had wondered why you guys bother to oven HT at all and don't just water drop from the mold. A soft core makes sense.

On the issue of expansion + hardness, you hoary headed veterans ever tried Pb/Sn/Cu? leftiye gave me the idea of trying it.

Conventional ovens work fine, once you get the thermostat set for the proper temperature and they hold temperature correctly instead of cycling. A good thermometer is necessary for repeat performance.

Things like Pb/Sn/Cu have been tried extensively. A simple combinations that works is best though.

[BABore]

What ovens are you guys using for oven HT? Always been curious about this. I assume you don't just do it in the kitchen. I had wondered why you guys bother to oven HT at all and don't just water drop from the mold. A soft core makes sense.

On the issue of expansion + hardness, you hoary headed veterans ever tried Pb/Sn/Cu? leftiye gave me the idea of trying it.

I do mine right in the kitchen range. I made up some special holding trays for the boolits so they are all standing up. Picture a large aluminum cribbage board with 1/2" holes and a bail handle. No need to worry amount cross contamination with food if your careful. Lead fumes well above the point a typical oven is even capable of. I use a Jenn-air oven and as mentioned, a good thermometer to calibrate the oven. I only rarely use the oven now as my WD boolits acheive the same hardness. In fact I tested different oven temperatures to get the right one that duplicates my WDing technique, so I get the same hard shell and softer core.

Yes, I have played around quite a bit with the copper additions. Copper and silver make for hardness and more importantly, toughness. Found it to work, but alot of fuss. Basically a crutch for an ill fitting boolit and so-so bbl. With a well fit boolit and decent bore you can get away with more normal alloys and have the same or better results.

[Alex Hamilton]

That's the whole point about weighing [match] boolits - eliminate flyers. It takes only a few minutes, and the results are worth it.

What do you use to weigh you boolits? I have ordinary Redding powder scales and althogh the arm is magnetically damped, it still takes some time to settle.

[Alex Hamilton]

Been there!! I've cut the lube(felix) all the way down to just the GC shank and one groove above it. It didn't make a difference.
I'm now trying lars 2500+ but I don't think it will make a differnce.
I still think it is voids!!!!

In that case, will you tells when you find out, because we could all be "suffering" without knowing it. I mean the average group size from a military rifle may be such that an odd flier might go unnoticed.

Would an X-ray machine show voids in lead?

[StarMetal]

In that case, will you tells when you find out, because we could all be "suffering" without knowing it. I mean the average group size from a military rifle may be such that an odd flier might go unnoticed.

Would an X-ray machine show voids in lead?

X-ray won't penetrate lead. That's why they use lead for shielding.

[qajaq59]

What do you use to weigh you boolits? I have ordinary Redding powder scales and althogh the arm is magnetically damped, it still takes some time to settle. My balance scale drove me nuts for weighing bullets, so this morning I ordered that $40 electronic scale that Midway has on clearance for $19.99.

[BABore]

What do you use to weigh you boolits? I have ordinary Redding powder scales and althogh the arm is magnetically damped, it still takes some time to settle.

I use a regular RCBS scale like your Redding. I pencil in a few marks above and below the -O- point to give me a rough estimate of +/- 0.25 grains and +/-0.5 grains. This changes slightly when going from 100 grain boolits to 500 grain one, but you get the point. Set the boolit on gently so you don't get the wild swings going on. After a bit you will get the feel as to where the needle will stop based on the swing range. I inspect the next to be weighed boolit while the the pointer is starting it's swaying and am taking it off even before it stops. Takes a bit to get a feel for it, but it goes pretty fast. I'm told faster than an electronic scale cause you can't see the swing.

Anymore, I only weigh 22 cal boolits for my Hornet. They will definetly benefit from an exact weight. A tiny boolit only takes a tiny void to make it a flyer. Match boolits in any caliber, could justify weight sorting. I only weighed alot of boolits initially to trouble shoot my technique and mold cavities. A micrometer should be used as well here.

[357maximum]

Say what you will, you two still don't know all the reasons 45 2.1 does that. Well I proably will never GET IT all Joebob, but I do know it works even if I am on an intellect level that will always fail to see the whole picture. I can see the pictures I want to without knowing all the super secret squirrel "WHY'S" I guess. The picture I get are small groups and brown antlered things hangin by their bones getting ready to be turned into steak. I guess if that is all the "BIG PICTURE" I am ever smart enough to "GET" ...I can still die a happy caster. I am not 100% sure"how" or "why" alot of the things I enjoy work.........does not stop me from enjoying them. WHEN YOU GET IT ALL FIGGERED OUT......YOU'RE DEAD. ...........so not in a big hurry to figger it all out so I just try to learn enough about the HOWHY's to get me by.

....so what's your point about some bad cast bullet as though you have never made any in your life. [smilie=1::kidding:

We all make boolits we are not proud of from time to time, but sending them out to somone else is not something most of us would do, but then again I think you may just be a bit "different" than alot of people.[smilie=1:.......not saying it is a bad thing but it may just be a case of "IT IS WHAT IT IS":mrgreen:


If someone reads this whole thread and ignores some of the warm air there is alot to be gleamed from this thread. Throw it all in the air as you read it......the effluent hot winds will remove the chaff from the wheat.

[StarMetal]

We all make boolits we are not proud of from time to time, but sending them out to somone else is not something most of us would do, but then again I think you may just be a bit "different" than alot of people.[smilie=1:.......not saying it is a bad thing but it may just be a case of "IT IS WHAT IT IS":mrgreen:


If someone reads this whole thread and ignores some of the warm air there is alot to be gleamed from this thread. Throw it all in the air as you read it......the effluent hot winds will remove the chaff from the wheat.

I kind of disagree with that being different. You got bullets you didn't think were well cast from that "old man", so that's two people a little different huh? And he and I got bullets from another member, I won't mention, that were so bad we just melted them. So now that's three people who have done it. Getting the drift here? [smilie=s:

By the way the bullets I send out spoken about were rejects. They weren't exactly for shooting. Want an opinion on my bullets ask BruceB about the 314299's I sent him and 9.3x62AL about the 30 Luger bullets I sent him. :bigsmyl2:

[357maximum]

Joe you are too easy . ;) But fun nonetheless. ;):-P

[StarMetal]

Joe you are too easy . ;) But fun nonetheless. ;):-P

What you're looking for Mike is that I'm honest and tell the truth about reloading and guns as far as I know it.

Do you really think with the shooting I've done that I would have done it with the lousy bullets I sent Bruce? Also my Hornet is shooting smaller groups then his is and at decent velocity. :violin:

[357maximum]

I don't think you could hit the broad side of a big ol red barn....from inside of said barn.:kidding::kidding::kidding:

BTW....that invite is still there. :-P

[StarMetal]

I don't think you could hit the broad side of a big ol red barn....from inside of said barn.:kidding::kidding::kidding:

BTW....that invite is still there. :-P

Who told you about the barn??? :brokenima[smilie=p:

[357maximum]

Who told you about the barn??? :brokenima[smilie=p:

A nice little well cared for sheep wearing a pink bow, now I also know where you get your lanolin.[smilie=1:

[303Guy]

Things like Pb/Sn/Cu have been tried extensivelyMore, more! This idea pulls strings in me. I can't get WW's but can get plenty lead pipe and lead sheeting which is mysterious stuff too - it's not all pure lead. A lot of the piping has big thick plumbers solder 'joints' on it. I can also get copper .....

By the the way, I have this neat little oven / grill thingy with a hot plate on top. Just the right size for heat treating boolits.

http://i388.photobucket.com/albums/oo327/303Guy/Boolit_Casting_Oven-Hotplate.jpg

[qajaq59]

303 Guy, what's the tin foil for?

[sagacious]

Isn't that heat wave going to be relative as mould temp goes up?
Bret,
If I understand you to mean, "Doesn't the wavelength of the heat wave increase as mold temp approaches closer to melt temp?", then the answer is of course yes.

We all know that heat input from molten lead increases mold temp. This heat input can be viewed as a wave that rises and then falls over time-- as mold temp rises and then falls. One will soon notice that with many molds a certain casting frequency causes a too-lengthy cooling period which is uncorrelated with reject rate. The mold is simply hotter than need be.

Some will set the mold aside to cool, or use multiple molds to give each a cooling period, and of course that can be very effective. But also, if one can distinguish the peak and trough of the wave, and control it through melt temp management, mold control, and casting rate, the production rate from one mold can be cranked up very high, as there is virtually no down time for cooling. This is possible if one can accurately guage the effect of the 'heat wave', and though it's effect diminishes as mold temp increases, there is a point where it's effect can me maximally utilized. For example, proper mold cooling with a wet towel just barely 'resets' the mold to just under or just at the temp where the heat wave is maximally effective.

Regards, and good shooting. :drinks:

[Dannix]

[Cu] Copper and silver make for hardness and more importantly, toughness. Found it to work, but alot of fuss. Basically a crutch for an ill fitting boolit and so-so bbl. With a well fit boolit and decent bore you can get away with more normal alloys and have the same or better results.
bbl? I had heard something about Cu before, but Cu really caught my eye when I went looking into creating a tough HP (http://castboolits.gunloads.com/showthread.php?t=76071). Not considering it as a replacement for a proper boolit, but as a HP toughener. Looking at leftiye's BHN numbers though, ~18BHN, it may be too hard and a sans-Cu, Pb/tin route for dual-alloy, soft nose boolits would be a better route.


Here's a 50/50 WW-Pb boolit that was water dropped for a 22 bhn shell hardness. 480 Ruger, 400 gr at 1,250 fps. Went through 1/2" osb, then into soft loam soil at 50 yards. Shot by you BTW.
http://castboolits.gunloads.com/attachment.php?attachmentid=22904&stc=1&thumb=1&d=1276609662


That's one sweet boolit! And in reference to 45 2.1's comment of simple + effective = best, I imagine that's better than an HP route for when deeper penetration is desired. Might the ~.30cal range be too narrow to keep a decent sized soft core though?

I've considered going with a dual alloy boolit for a softer nose. But in the interest of keeping it simple, also looking to try mono, water dropped and then nose softening with a torch. But I'll lurk craigslist if you think the oven route would be worth trying for the smaller, .30 cal diameter range.

[303Guy]

... what's the tin foil for? It covers a blanket of ceramic wool insulation.

[303Guy]

So I refilled my melting pot with fresh scrap - lead pipe, some lead sheeting and some plumbers solder (from the lead pipe). Take a look.

http://i388.photobucket.com/albums/oo327/303Guy/157gr_mysteryalloy.jpg

Even the first one was photogenic. I tried a cooler mold then a cold mold and still they came out good.

They even hold together when fired into sand (sort of).

http://i388.photobucket.com/albums/oo327/303Guy/20gr2205_146PP.jpg It 'splashed'.

Weight retension was 82% (loosely speaking).

[sagacious]

So I refilled my melting pot with fresh scrap - lead pipe, some lead sheeting and some plumbers solder (from the lead pipe). Take a look.

Looks good! So, do you reckon the addition of tin solder did help?

[303Guy]

I don't know. It seems that way but then the previous lot had the same amount of solder added to it too and that produced pooh. I suspect the lead sheet had something in it. What ever it is it is very forgiving stuff - the best casting alloy I can remember. Oh yes, it heat treats. Lead-tin is not supposed to do that is it? There doesn't seem to be any frosting with hot melt into a hot mold. Would that indicate an absense of antimony? Tin is supposed to give fluidity and good fill out right? It also lacks that ringing sound antimonial alloys produce but it's not as dull sounding as pure lead.

Correction!:!:

The poohey castings were from before I added the first piece of solder. The first solder addition lot would still have had antimony and whatever else in it.:idea:

I've just taken another hardness reading on the sample I oven heat treated this afternoon - it has hardened considerably since the treatment. I wonder how long it will stay hard?:roll: I'll heat treat a few more and test fire them tomorrow.

[Bret4207]

Bret,
If I understand you to mean, "Doesn't the wavelength of the heat wave increase as mold temp approaches closer to melt temp?", then the answer is of course yes.

We all know that heat input from molten lead increases mold temp. This heat input can be viewed as a wave that rises and then falls over time-- as mold temp rises and then falls. One will soon notice that with many molds a certain casting frequency causes a too-lengthy cooling period which is uncorrelated with reject rate. The mold is simply hotter than need be.

Some will set the mold aside to cool, or use multiple molds to give each a cooling period, and of course that can be very effective. But also, if one can distinguish the peak and trough of the wave, and control it through melt temp management, mold control, and casting rate, the production rate from one mold can be cranked up very high, as there is virtually no down time for cooling. This is possible if one can accurately guage the effect of the 'heat wave', and though it's effect diminishes as mold temp increases, there is a point where it's effect can me maximally utilized. For example, proper mold cooling with a wet towel just barely 'resets' the mold to just under or just at the temp where the heat wave is maximally effective.

Regards, and good shooting. :drinks:

Okay, now I got it. Balance the tempo and pot heat for max casting performance. You just worded it in a way I had trouble following, ie- big words corn-fuze me!

[kbstenberg]

As a newby (a year of casting) I find the information in this thread super informative. If i could muddle through, some points still unclear to me.
So far all you have talked about is rifle bullets. I assume (ya i know what you get when you assume.) Both rifle an pistol bullets get the superior results using this system!
Comments were made about the alloy used. So most of the time 50/50 + small% tin , Clip on/ soft is used for the mid to higher velocity hunting loads an you still get descent expansion.
I am still trying to wrap my head around what i am reading. An these are the 2 questions that come to mind!!!!
Kevin

[BABore]

Yes, the same technique is used for pistol as well as rifle. Some of us here shoot our pistols like rifles as far as range and accuracy expectations.

I and many others have shot water dropped 50/50, WW-Pb alloy, at full jacketed velocity with accuracy. Even though they usually only attain 22 bhn, it's not all about hardenss. Toughness is a very important factor as well. Also, higher antimonial alloys propigate alot of the antimony to the outside of the boolit. At high velocity this antimony will foul the bbl with a light gray, powdery wash which will abraid later boolits. Reducing the antimony by half will eliminate much of this fouling which will allow you to shoot faster and longer between cleanings. About the only big downside is cure time. It takes 50/50 alloy a couple weeks to start to be consistent. A couple months or longer is even better. Hard to stomach when your just building an inventory up and want to shoot. Shooting year old boolits will often surprise you compared to what they did when young.

[45 2.1]

It takes 50/50 alloy a couple weeks to start to be consistent. A couple months or longer is even better. Hard to stomach when your just building an inventory up and want to shoot. Shooting year old boolits will often surprise you compared to what they did when young.

Three year old boolits will surprise you more than year old ones.

[BABore]

Three year old boolits will surprise you more than year old ones.

Yeah, cause you had thought you had lost them for sure. :shock: :bigsmyl2:

[45 2.1]

Yeah, cause you had thought you had lost them for sure. :shock: :bigsmyl2:

No, those occupy the shelf under the bench. I have twenty year old ones down there also..................... Where's yours!

[BABore]

No, those occupy the shelf under the bench. I have twenty year old ones down there also..................... Where's yours!

Sorry. I only have boolits that are 5 years or so old. Some of those I have even melted back down. I'm of a more practical sort. I fiqure iff'in it's sat around for that long without being used or needed, then it probably wasn't worth saving to begin with. Beside's, what good does it do to develope a load for a 5 year old booit, find out it's the best thing since sliced bread, then run out. You would have to make a yearly run of that boolit for stock based on a maybe.

Then again, maybe we can look forward to you being on a future installment of "Hoarder's".[smilie=l:

[StarMetal]

Sorry. I only have boolits that are 5 years or so old. Some of those I have even melted back down. I'm of a more practical sort. I fiqure iff'in it's sat around for that long without being used or needed, then it probably wasn't worth saving to begin with. Beside's, what good does it do to develope a load for a 5 year old booit, find out it's the best thing since sliced bread, then run out. You would have to make a yearly run of that boolit for stock based on a maybe.

Then again, maybe we can look forward to you being on a future installment of "Hoarder's".[smilie=l:

Master Pu is going to punish you Grasshopper!!!! :bigsmyl2:

[BABore]

Master Pu is going to punish you Grasshopper!!!! :bigsmyl2:

Naw! He doesn't have cable or dish, so he'll never see what I'm referring to.

Can you picture Master Pu, standing in the yard with his head in his hands and tears running down his face, while a cleanup crew hauls crates of musty ole boolits out to a giant smelting pot.:bigsmyl2:

[kbstenberg]

A yungest grass hopper would request to ask another question. With the higher BHN of your style of casting, You still get moderate to good expansion? Young grasshopper will listen to the masters intently
Kevin.
I thought of more questions at work today but im having a brainfart an cant remember.

[sagacious]

I suspect the lead sheet had something in it. What ever it is it is very forgiving stuff - the best casting alloy I can remember. Oh yes, it heat treats. Lead-tin is not supposed to do that is it? There doesn't seem to be any frosting with hot melt into a hot mold. Would that indicate an absense of antimony? Tin is supposed to give fluidity and good fill out right? It also lacks that ringing sound antimonial alloys produce but it's not as dull sounding as pure lead.
303Guy,
Lead sheet and pipe commonly has a percent or two of Sb. Since it's cold-rolled, it softens, and loses the 'ring'. My push-through molds give shiny bullets with Pb/Sb alloys, so lack of 'frosting' is probably not diagnostic in this case. Your previous 'cold-shut' problems also indicate that the mold gives rapid cooling, and that usually precludes frosty bullets. It seems likely that your lead sheet does contain some Sb.


Correction!:!:

The poohey castings were from before I added the first piece of solder.
The addition of even a small amount of Sn can very effectively reduce/eliminate the casting defects you were experiencing earlier. In some situations, seemingly insignificant alloy changes can result in big changes-- either positive or negative. If your lead sheet does contain some Sb, then the effect of adding a little Sn would produce exactly the casting differences you report.

Good luck, and good shooting.

[sagacious]

Okay, now I got it. Balance the tempo and pot heat for max casting performance. You just worded it in a way I had trouble following, ie- big words corn-fuze me!
Very good-- could be that I just didn't explain it very well. The best lead casters I know are masters at anticipating, balancing, and managing temperature. I am convinced that's what it comes down to. All other concerns are secondary. Mastery of temp control can give good results with substandard equipment and materials, but poor management of temp control can give lousy results with even the best equipment and materials.

[303Guy]

Thanks sagacious.

It's all making sense now. I've dickied the alloy a little now and hot water dropping yeilds quick results with followed hardening following in a short time. My 'measuring' system is very logrithmic and I cannot detect changes once it starts to get quite hard. I can still scratch it with a thumbnail 'though. Well as hard (which actually not that hard) as it is, it is very ductile! Ummm... the dicky-ing was the addition of a small amount of copper. (Easier than one might think).

I considered the mold effect on frosting but decided it was the alloy itself. Even the sprue puddle takes on a shine as it shrinks and freezes. (Although I am quite sure there is some antimony in it).

http://i388.photobucket.com/albums/oo327/303Guy/LedTinCopperAlloy.jpg The cat sneeze fired boolit has 100% weight retention.

[sagacious]

Ummm... the dicky-ing was the addition of a small amount of copper. (Easier than one might think).
303Guy,
If you would, please detail your alloying process.

[303Guy]

Yes of course. Take some copper, tin it with soft electrical solder and submerge it in the melt and wait. The copper just dissolves! It's so easy I couldn't believe it! My understanding it that lead will only dissolve so much copper when it is already alloyed with tin. Hopefully, the most copper to get dissolved will be controlled by the solubility in tin. I added very little actually, but the results are obvious. The sprues now have all the colors of the rainbow! Mostly deep purple. I took a chance and got away with it. I did not ruin my 'mystery' alloy!:mrgreen:

The impression I am getting is that surface hardness is increased somewhat without loss of ductility. For now this is a novelty.:mrgreen:

[303Guy]

Say, you know, this thread is full of all kinds of useful information on casting - do you folks think it might be helpful to others if'n it were to made a sticky? What do you moderators think? (I've learned a heap from it!)


As a newby (a year of casting) I find the information in this thread super informative.

Just a thought.:roll:

[sagacious]

The sprues now have all the colors of the rainbow! Mostly deep purple. The impression I am getting is that surface hardness is increased somewhat without loss of ductility. For now this is a novelty.:mrgreen:
OK, you're dissolving with tin. I had thought you meant copper into pure lead.

What suggests to you that 'surface hardness' is increased?

Try alloying copper into pure lead-- colors galore. That's the ugly underbelly of adding copper, the oxidation goes way up.

[303Guy]

What suggests to you that 'surface hardness' is increased? Just by 'measuring'. Un-water dropped the surface has the 'hardness' of the alloy prior to the addition of copper when water dropped. (I'm only doing a crude comparative 'measuring').

[Bret4207]

Very good-- could be that I just didn't explain it very well. The best lead casters I know are masters at anticipating, balancing, and managing temperature. I am convinced that's what it comes down to. All other concerns are secondary. Mastery of temp control can give good results with substandard equipment and materials, but poor management of temp control can give lousy results with even the best equipment and materials.

Yup, just like I've been saying- mould temp is relatively more important than pot temp and it's not the tool, it's the guy running it.

Good post.:D

[Dannix]

Awesome you got some sweet boolit action going down now 303. That cat sneeze, was that into sand? That velocity? Wish your Sn/Sb/Cu percentages were known, but I guess that's just a trade off from using scrap.

This thread along with the latex thread has given me more insight on alloys than any other reading I've done. Awesome forum we got here. A big thanks to the seasoned veterans!

[BABore]

A yungest grass hopper would request to ask another question. With the higher BHN of your style of casting, You still get moderate to good expansion? Young grasshopper will listen to the masters intently
Kevin.
I thought of more questions at work today but im having a brainfart an cant remember.

The casting style allows for consistency. Consistent mold temperature. Consistent size and weight. Consistent boolit temperature of the boolit hitting the water bucket.

It's also in the alloy. If you ran this casting method with straight WW's, you would get the same boolit hardness and charteristics as oven heat treating them at a slightly lower temperature. Go back and re-read my earlier post where I mention the temperature threshhold for heat treating. If I were to get the mold up to proper temp and cut the sprue real early, likely tearing out a big chunk and smearing lead, I would be well above the minimum HT temp. threshhold. When water dropped, this hot of a boolit would get hard almost all the way to the core. Wait a bit longer to cut the sprue and dump and you will be slightly cooler and just above that threshhold. Hard skin and softer core.

Do this with straight WW's and you will have a good hard boolit shell and a softer inner core. The antimony level in WW's is still high enough that most times expansion will rivet up and fragment into small pieces. Even annealing the nose of a HTWW boolit will show this. If you cut the WW's with half Pb you gain more ductility. When heat treated, the alloy is still ductile and tough. An air cooled 50/50 boolit will expand very nice and usually will roll back and hold the mushroom. When you combine a hard, tough outer shell with a soft core your kind of simulating a jacketed bullet. The tough copper jacket helps control the over expansion of the soft lead core.

Getting the drop temperature of your alloy right is something that requires testing in wet pack. Once you establish a good baseline, your all set.

[303Guy]

That cat sneeze, was that into sand? That velocity?Yes it was into sand. The sand itself is a special quality being very fine and soft. It gets pulverized by the continuous impacts. The surprizing thing was the penetration that little expanded boolit had in it.

Velocity unknown. Howerver, I do have a Chrony and since the cat sneeze load is, well, cat sneeze, I shall be setting up for a little bit of chronographing in my shed! (But don't tell my neighbors! [smilie=1: )

The antimony content is likely to be very low but not absent. I have a few samples of different alloys that did amazing things that I would like to get analized. I had one alloy that would cast a hard base and soft nose - the nose portion was actually frosted. Expansion into wet rags stopped at the interface. (The mold has a differential cooling rate by design to prevent voids from forming as it's a nose pour. The idea was that the hot mold would cool from bottom up with the sprue puddle freezing last so as to feed metal into the contracting boolit core. It worked.)

[kbstenberg]

Could i ask several more questions that pertain to related aspects?
Is it easier using a 1 or 2 cavity mold rather than a mold of 4 or more cavities? I would imagine using the smaller molds during the learning stages, then progressing to the larger molds.
Do the bullets molded with the faster/ hotter molds produce frostier bullets or even bullets that have a galvanized appearance?
What other subjects are to be considered that aid for a more consistent cast bullet
An thank you Babore for explaining an re-explaining till it finally sunk in to this thick Mellon. Being new i am up to learning anything that will help. Not to brag. This Summer iv shot 5 or 6oo rounds of 44 mag & 30/30 ( which is a lot for me). An because of what Ive learned here. I haven't had to de-lead either of the guns i have been shooting. All due to the Cast Boolit website.

[leftiye]

Dannix, To be honest Ba Bore was the one who told me how to alloy copper into lead. I think that 303 has taken it to the next level maybe. It may be possible to simply drop the correct amount of copper into solder containing the right amount of tin for the batch to be made, and maybe it'll just dissolve as 303 described. As for the 18 bhn alloy (89% leaad, 10%tin, 1% copper) being too hard, make an X boolit out of it maybe. It should hold together extremely well. Or, paper patch your hollow point and shoot it at 2500 fps.

Someone else here previously - and my ALS prevents me from remembering just who - did a quite scientific stuudy of toughness and his results were that the percent of antimony that produced the best toughness was about 2%. When augmented with tin, that was best at 2% also (IIRC).

And again, it is very workable to accurately, and easily control mold temperature by means of an electric mold heater worked into your sequence. Not that it is good, but it is possible to cast frosted boolits with alloy that is cooler than 600 degrees. Or even get the mold so hot that you can pour the alloy back out of the mold - even after a considerable wait. The point being that if you use an IR thermometer to determine your mold temp, you can determine BaBore's ideal temp and hold it.

[303Guy]

Someone else here previously - and my ALS prevents me from remembering just who - did a quite scientific stuudy of toughness and his results were that the percent of antimony that produced the best toughness was about 2%. When augmented with tin, that was best at 2% also (IIRC). Now I'm intested! Anyone remember who it might have been or the threat it might be in?

Those percentages and toughness assesment kinda ring true from what I have played around with before - just at a guess but I could be way off.

[lwknight]

I had done some testing with paper patching soft lead for my 44mag and when I used 2.5% tin the result was 99.9% weight retention and an inside out mushroom. You have seen this pictures before.
http://i688.photobucket.com/albums/vv246/lwknight/Bfr_aft.jpg

I never had a "J word" bullet do any better.

[Dannix]

leftiye, I thought it was 5% and 5%, not 2% and 2%? I think it's in the stickies.

Nice boolits lwknight!

[Cherokee]

Good info here, keep it coming....

[Dannix]

I came across this thread today and after doing some re-reading decided to give it a bump for others.

[degruix]

Thank you Dannix, I have printed out part of this thread to insure the information will not be lost.

[Iron Mike Golf]

Good info. As I learn more and get more experience, re-reading things is a real benefit, because I understand it better.

Regarding Sb, Sn and toughness, the idea I caught from that thread was keeping those at 1:1 to each other in increasing increases toughness a lot when water cooled or heat treated. Additional Sb above that may increase hardness but at the loss of toughness.